In order to be able to steer an aircraft while it is running on the ground, it is necessary to provide steerable landing gear, with steering generally being provided for the auxiliary landing gear (nose wheel or tail wheel). Steerable landing gear includes a strut for fixing to the aircraft (generally retractably), with a rotary tube mounted to rotate relative to the strut, and a sliding rod mounted to slide inside the rotary tube and connected thereto by a scissor linkage, with the bottom end of the sliding rod carrying the wheels of the landing gear. In order to steer its wheels, the landing gear includes steering apparatus generally comprising either an actuator fitted with a rack associated with a toothed ring carried by the rotary tube, or else a rotary hydraulic motor fixed to the strut and including a gear wheel engaging with a toothed ring carried by the rotary tube.
U.S. Pat. Nos. US-A-3 124 034 and US-A-4 313 364 both describe landing gear steering apparatuses each comprising a body fixed to a landing gear strut, a crank disposed to rotate inside the body about an axis of rotation parallel to an axis of rotation of a wheel support, link means linking one end of the crank with the wheel support, and at least two actuators extending perpendicularly to the axis of rotation of the crank, each of said actuators having one end hinged to the body to be able to pivot about a pivot axis parallel to the axis of rotation of the crank and one end hinged to a crank pin of the crank, with the actuators being connected to distribution means for distributing a driving fluid. However, in both cases the actuators are fed from distribution members which are complex, thereby reducing maneuvering speed and accuracy of the steering apparatuses.
An object of the present invention is to provide landing gear steering apparatus having distribution means which are simple in structure and which adapt automatically to landing gear steering.